WO2018058576A1 - Data modulation method and encoder - Google Patents

Abstract

Embodiments of the present application provide a data modulation method and an encoder for providing optical fiber with better resistance to nonlinear damage. A technical solution provided by the present application is as follows: an encoder determining a first constellation point from an at least two-dimensional first constellation diagram in multi-dimensional constellation diagrams, and determining a second constellation point from another at least two-dimensional second constellation diagram in the multi-dimensional constellation diagrams, wherein the first constellation point and the second constellation point cannot be constellation points having a maximum amplitude in respective constellation diagrams at the same time; the encoder matching the first constellation point and the second constellation point to generate a constellation combination point; the encoder receiving a bit sequence carrying digital information; the encoder mapping the bit sequence into a symbol for transmission by means of a mapping table of the constellation combination point, wherein the mapping table is pre-stored by the encoder; and the encoder sending the symbol to a digital-analog converter.

Description

Data modulation method and encoder Technical field

The embodiments of the present application relate to the field of communications, and in particular, to a data modulation method and an encoder.

Background technique

For a long time, larger transmission capacity, longer transmission distance and better transmission effect are the goals pursued by optical communication systems. In recent years, the rapid increase in transmission distance and capacity brought about by the application of a large number of new technologies has led to the development of optical communication systems exceeding the growth rate defined by Moore's Law. Although the current development of the information industry has slowed down, with the globalization of information and the emergence of new data services, the development of ultra-long-distance, ultra-large-capacity optical communication systems will remain one of the themes of future research. The current optical communication system is based on high-order mainstream mode polarization multiplexing 16 orthogonal amplitude modulation (English name: Polarization Division Multiplexed 16 Quadrature Amplitude Modulation, referred to as: PDM-16QAM), the spectral efficiency is 8 bits per second per Hz bits / The transmission distance of the s/Hz 200G scheme is less than 600 kilometers. If you continue to extend the transmission distance, you will receive linear gain (such as optical signal-to-noise ratio (Optical Signal Noise Ratio, OSNR)) and fiber nonlinear damage (such as self-phase modulation (English name: Self Phase Modulation, SPM for short). ), cross-phase modulation (English full name: Cross Phase Modulation, referred to as: XPM), four-wave mixing (English full name: Four Wave Mixing, referred to as: FWM) and other major factors.

For the current PDM-16QAM, the joint orthogonal component (English full name: Inphase/Quadrature, referred to as: I/Q) and two polarization states (X, Y) in the four-dimensional vector (Ix, Qx, Iy, Qy) space There is a 16x16=256 combination, referred to as 256 points, and the minimum Euclidean distance is 1.

However, the PDM-16QAM has no compensation design for nonlinear damage, resulting in low resistance of the fiber to nonlinear damage.

Summary of the invention

The embodiment of the present application provides a data modulation method and an encoder for improving the resistance of an optical fiber to nonlinear damage.

In a first aspect, an embodiment of the present application provides a data modulation method, including: an encoder selecting a first constellation point from a first constellation diagram of at least two dimensions in a multi-dimensional constellation, from the multi-dimensional constellation Selecting a second constellation point in the other at least two-dimensional second constellation map, where the first constellation point is different from the second constellation point, and is the largest constellation point in the respective constellation, that is, when the first constellation point is the largest amplitude The second constellation point is any point of the second constellation point except the largest amplitude constellation point, which is an at least 4-dimensional constellation including the joint orthogonal component I/Q; The encoder pairs the first constellation point with the second constellation point to generate a constellation combination point; secondly, after the encoder receives the bit sequence carrying the digital information, the encoder can be combined with the constellation according to the pre-stored The mapping table corresponding to the point maps the bit sequence to a symbol for transmission; finally, the encoder transmits the symbol to the digital to analog converter.

In the embodiment of the present application, the data modulation method is mainly used for quadrature amplitude modulation based on a multi-dimensional space including joint orthogonal component I/Q and other dimensions, the method comprising: the encoder from the first dimension Determining a first constellation point in the first constellation diagram, and determining a second constellation point from a second constellation diagram of the second dimension, the first constellation point being different from the second constellation point being the largest constellation point in the respective constellation diagram The encoder pairs the first constellation point with the second constellation point to generate a constellation combination point; the encoder receives a bit sequence carrying digital information; the encoder maps the bit sequence through a mapping table of the constellation combination point For symbols for transmission, the mapping table is pre-stored by the encoder; the encoder sends the symbol to a digital to analog converter.

In the embodiment of the present application, the encoder selects constellation points in other dimensions and pairs them to generate constellation combination points, and discards the constellation combination points generated by the largest constellation points in the constellation diagrams of other dimensions, which can effectively reduce the constellation combination. The peak power of the point, which effectively improves the resistance of the fiber to nonlinear damage.

Optionally, the other dimensions are at least one of a polarization state, a time, a wavelength, a subcarrier, a mode of a multimode fiber, and a core of the multi-core fiber. In practical applications, the specific dimensions used are not limited here.

Optionally, the multi-dimensional constellation is polarization multiplexing 16 orthogonal amplitude modulation PDM-16QAM, and the PDM-16QAM is based on a four-dimensional space including the I/Q, the first polarization state and the second polarization state, the first constellation The figure includes the I/Q and the first polarization state, the second constellation diagram includes the I/Q and the second polarization state, and the first constellation diagram and the second constellation diagram are coordinate diagrams of 16 constellation points. The abscissa of the graph is the I, and the ordinate of the graph is the Q.

In the embodiment of the present application, the orthogonal amplitude modulation is polarization multiplexing 16 orthogonal amplitude modulation PDM-16QAM, the first dimension is a first polarization state, and the second dimension is a second polarization state, and the PDM-16QAM is based on Including the I/Q, the first polarization state and the four-dimensional space of the second polarization state, the first constellation diagram and the second constellation diagram are coordinate diagrams of 16 constellation points, and the abscissa of the coordinate graph is the I The ordinate of the graph is the Q.

In the actual application, the multi-dimensional constellation can also be in the form of PDM-64QAM, PDM-256QAM, etc., and is not limited herein. In the embodiment of the present application, PDM-16QAM is taken as an example for description.

Optionally, based on the foregoing PDM-16QAM and the first polarization state and the second polarization state, the encoder may further determine the first constellation point and the second constellation point in the following manner, as follows:

In a possible implementation, the encoder arbitrarily selects the first constellation point from the first constellation diagram, and selects the second constellation point in the second constellation diagram, and the encoder selects the first constellation point and the The second constellation point should ensure that the minimum Euclidean distance between the constellation points generated by the pairing of the first constellation point and the second constellation point is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times.

In the embodiment of the present application, the minimum Euclidean distance between the constellation points of the constellation may be other multiples of the minimum Euclidean distance between the constellation points of the PDM-16QAM, such as 2, 3, etc., as long as the constellation combination point is ensured as much as possible The minimum Euclidean distance can be maximized. The specific multiple is not limited here.

In the solution provided by the embodiment of the present application, the encoder maximizes the minimum Euclidean distance between the first constellation point and the constellation combination point generated by the second constellation point, and can effectively improve the linear gain and spectrum of the optical fiber. effectiveness.

In a possible implementation manner, if the first constellation diagram and the second constellation diagram are the same as the rectangular constellation diagram, the constellation points in the first constellation diagram are respectively allocated to the center of the origin, and the three are not equal to each other. On the three rings with a positive radius, the above three rings are sequentially recorded as ring 1, ring 2, and ring 3 from the inside to the outside, wherein the ring 1 is assigned 4 constellation points, and the ring 2 is assigned 8 For the constellation points, four constellation points are allocated on the ring 3. Similarly, the constellation points in the second constellation diagram are respectively allocated to three rings with the origin as the center and three mutually unequal positive numbers as the radius. In the above, the above three rings are sequentially recorded as ring 4, ring 5, and ring 6 from the inside to the outside, wherein the ring 4 is assigned 4 constellation points, and the ring 5 is assigned 8 constellation points. Four constellation points are allocated on the ring 6.

On this basis, in one possible manner, the encoder arbitrarily selects the first constellation point from the ring 1, and then the encoder selects the second constellation point from the ring 4 or the ring 5 or the ring 6. And a minimum Euclidean distance between the constellation combination points generated by pairing the first constellation point and the second constellation point is a minimum Euclidean distance between constellation points of the PDM-16QAM

Times.

In another possible manner, the encoder arbitrarily selects the first constellation point from the ring 2, and then the encoder selects the second constellation point from the ring 4 or the ring 5, the first constellation point and the The minimum Euclidean distance between the constellation combination points generated by the second constellation point pairing is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times.

In another possible manner, when the encoder selects a constellation point (-3+3j) or a constellation point (3-3j) from the ring 3 as the first constellation point, the encoder is from the constellation point (1+1j) ), the constellation point (-1+3j), the constellation point (1-3j), and the constellation point (-1-1j) are arbitrarily selected as the second constellation point; the encoder selects the constellation point from the ring 3 ( -3-3j) or constellation point (3+3j) as the first constellation point, the encoder from the constellation point (3+1j), constellation point (-1+1j), constellation point (-3-1j) And arbitrarily selecting a point in the constellation point (1-1j) as the second constellation point.

In another possible manner, the encoder selects a constellation point from the ring 3 from the first target constellation point arbitrarily selected in the ring 1, from the arbitrarily selected second target constellation point in the ring 2 (-3+ 3j) or a constellation point (3-3j) as a third target constellation point and a constellation point (-3-3j) or a constellation point (3+3j) from the ring 3 as a fourth target constellation point as the first constellation Point; then the encoder selects a fifth target constellation point from the ring 4 or ring 5 or the ring 6, from the ring 4 or the sixth target constellation point selected in the ring 5, from the constellation point (1+1j ), the constellation point (-1+3j), the constellation point (1-3j), and the constellation point (-1-1j) are arbitrarily selected as the seventh target constellation point and the constellation point (3+1j), the constellation point ( -1+1j), arbitrarily selecting a point in the constellation point (-3-1j) and the constellation point (1-1j) as the eighth target constellation point as the second constellation point, the first target constellation point and the fifth target The minimum Euclidean distance between the constellation combination points generated by the constellation point pairing is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times, the minimum Euclidean distance between the constellation combination points generated by pairing the second target constellation point and the sixth target constellation point is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times.

In another possible manner, the encoder arbitrarily selects the first constellation point from the ring 1; then the encoder arbitrarily selects the second constellation point from the ring 5, the second constellation point and the first constellation The minimum Euclidean distance between the constellation combination points generated by the point pairing is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times.

In another possible manner, the encoder arbitrarily selects the first constellation point from the ring 2, and then the encoder selects the second constellation point from the ring 4, the second constellation point and the first constellation point The minimum Euclidean distance between the constellation points generated by the pairing is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times.

In another possible manner, the encoder arbitrarily selects the first constellation point from the ring 2, and then the encoder selects the second constellation point from the ring 5, the second constellation point and the first constellation point The minimum Euclidean distance between the constellation combination points generated by the pairing is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times.

In another possible manner, the encoder will select an arbitrarily selected seventh target constellation point from the ring 1 and an arbitrarily selected eighth target constellation point in the ring 2 as the first constellation point; the encoder will a ninth target constellation point selected in the ring 4, a tenth target constellation point selected from the ring 5 as the second constellation point, and a constellation combination point generated by pairing the seventh target constellation point with the ninth target constellation point The minimum Euclidean distance between the minimum Euclidean distances between the constellation points of the PDM-16QAM

The minimum Euclidean distance between the constellation combination points generated by pairing the eighth target constellation point with the tenth target constellation point is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times.

In the embodiment of the present application, the encoder ensures that the minimum Euclidean distance between the constellation points of the constellations is the minimum Euclidean distance between the constellation points of the PDM-16QAM.

Double can effectively improve the linear gain and spectral efficiency of the fiber. In the combination of the 96-point combination generated by one of the possible modes and the 64-point combination generated by one of the possible modes, it is more effective to ensure good linear gain, and it is also possible to ensure that the spectral efficiency can be 6.5. Bits per second per Hz.

In the 96-point combining mode, before the encoder maps the bit sequence through the mapping table of the constellation combination point to the symbol for transmission, the encoder needs to determine the mapping of the constellation combination point according to the combined binary data encoding manner. The table is stored and stored. The specific implementation is as follows:

The encoder determines a number of binary coded bits according to a first preset condition of the first bit sequence and the adjacent second bit sequence joint signal feature, wherein the first bit sequence includes a first sub-packet, a second sub-packet, and a third a sub-packet, the second bit sequence includes a fourth sub-packet identical to the first sub-packet, a fifth sub-packet identical to the second sub-packet, and a sixth sub-packet identical to the third sub-packet, The first sub-packet includes a constellation combination point formed by a constellation point in the ring 1 and a constellation point of the ring 5, and a constellation combination point formed by a constellation point in the ring 2 and a constellation point of the ring 4, the second sub-portion The packet includes a constellation combining point formed by a constellation point in the ring 2 and a constellation point in the ring 5, the third sub-packet including a constellation point in the ring 1 and a constellation point of the ring 4 and a constellation point of the ring 6 The constellation combination point formed, the constellation point (-3+3j) or the constellation point (3-3j) in the ring 3 and the constellation point (1+1j) in the ring 4, the constellation point in the ring 5 (-1+3j) ), the constellation combination point of the constellation point (1-3j) in the ring 5 and any one of the constellation points (-1-1j) in the ring 4, and the constellation point (-3-3j) in the ring 3 or Constellation point (3+3j) and constellation point (3+1j) in the ring 5, constellation point (-1+1j) in the ring 4, constellation point (-3-1j) in the ring 5, and the ring 4 Any constellation point (1-1j) arbitrarily selecting a constellation combination point formed by a constellation point; then, the encoder generates the first bit sequence and the second bit sequence according to the number of binary coded bits and a second preset condition Mapping table. The first preset condition is that the constellation points in the first constellation diagram are represented by 3 bits, and the constellation points in the second constellation diagram are represented by 2 bits, and the first bit sequence and the second bit sequence are in the second bit sequence. The sub-packet combination is represented by 3 bits, wherein the sub-packet combination excludes the combination of the third sub-packet and the sixth sub-packet; the second preset condition is that the adjacent constellation points in the constellation diagram have the smallest Euclidean distance, then Binding the binary bits of the minimum bit gap, the same constellation point of not less than the first preset threshold number in the same sub-packet encodes the same binary bit, and the same constellation within the different sub-packets not less than the second preset threshold number The dot encodes the same binary bit; the signal is characterized by a character, a time slot, a wavelength, a subcarrier, a mode of a multimode fiber, and a core of a multi-core fiber.

In practical applications, when the receiver side of the optical transmission system performs the decision constellation point, the receiving end can perform calculation in the eight-dimensional space in combination with the two signal features, and the training sequence adopts the formulas MeanA _xr1 , A _xi1 , A _Yr1 , A _yi1 , A _xr2 , A _xi2 , A _yr2 , A _yi2 estimate the respective average values of the 8192 points of the two signal characteristics, and then adopt the following formula:

Mininal(R _xr1 -A _m,xr1 ) ² +(R _xi1 -A _m,xi1 ) ² +(R _yr1 -A _m,yr1 ) ² +(R _yi1 -A _m,yi1 ) ² +(R _xr2 -A _m,xr2 ) ² +(R _xi2 -A _m,xi2 ) ² +(R _yr2 -A _m,yr2 ) ² +(R _yi2 -A _m,yi2 ) ² (m=1,2,...,8192) For the calculation of the Euclidean distance, the point with the smallest distance is selected as the final judgment result. If the encoder adopts the scheme of the 96-point constellation combination point, the receiver end of the optical transmission system can determine the training sequence by using the formulas MeanA _xr , A _xi , A _yr , A _yi when determining the constellation point. The average of 96 points in the signal characteristics, and then use the following formula:

Mininal(R _xr -A _m,xr ) ² +(R _xi -A _m,xi ) ² +(R _yr -A _m,yr ) ² +(R _yi -A _m,yi ) ² (m=1,2 ,...,96) Select the result of the smallest Euclidean distance from the 96 results of each signal feature, and finally make a final decision based on 4*4=16 possibilities of two adjacent characters, which can be extremely Reduce the amount of calculations. Wherein, the receiver end can select a plurality of Euclidean distances among the 96 results of each signal feature, that is, the result of selecting the five Euclidean distances to be the smallest, or the result of selecting the six Euclidean distances, the specific The values are not limited here.

In the solution provided by the embodiment of the present application, the encoder can further reduce the constellation combination point generated by the pair of constellation points with the largest amplitude, which can further reduce the nonlinear damage, and the encoder further constrains the generation of the mapping table by using various conditions, thereby Effectively reduce the bit error rate.

The encoder may generate the mapping table by using the first bit sequence and the second bit sequence according to the number of the binary coded bits and the second preset condition. The encoder may have the following example: the encoder in the first constellation diagram ( -1+3j) and (-1+1j) are encoded as 000, then the encoder encodes (-1+1j) in the second constellation diagram to 00, and (1-1j in the second constellation diagram) Encoding to 11, encoding (-3+1j) in the second constellation diagram as 10, and encoding (3-1j) in the second constellation diagram as 01 to obtain the mapping table;

or,

The encoder encodes (-1+3j) and (-1+1j) in the first constellation into 000, and the encoder encodes (-1+1j) in the second constellation into 10, Encoding (1-1j) in the second constellation diagram to 11 and encoding (3-1j) in the second constellation diagram as 00 to obtain the mapping table;

or,

The encoder encodes (-1+3j) and (-1+1j) in the first constellation diagram to 001, and the encoder encodes (-1+1j) in the second constellation diagram to 00, Encoding (1-1j) in the second constellation diagram to 11, encoding (-3+1j) in the second constellation diagram as 10, and encoding (3-1j) in the second constellation diagram as 01 obtain the mapping table;

or,

The encoder encodes (-1+3j) and (-1+1j) in the first constellation diagram to 001, and the encoder encodes (-1+1j) in the second constellation diagram to 10. Encoding (1-1j) in the second constellation diagram to 01, encoding (-3+1j) in the second constellation diagram as 00, and encoding (3-1j) in the second constellation diagram as 11 get the mapping table.

In a second aspect, an embodiment of the present application provides an encoder having a function of implementing an encoder in the foregoing method. This function can be implemented in hardware or executed by hardware. achieve. The hardware or software includes one or more modules corresponding to the functions described above.

In a possible implementation manner, the encoder includes: a receiving module, a processing module, and a sending module;

The processing module is configured to determine a first constellation point from the at least two-dimensional first constellation diagram in the multi-dimensional constellation, and determine a second constellation point from the other at least two-dimensional second constellation in the multi-dimensional constellation And the first constellation point is different from the second constellation point as the largest constellation point in the respective constellation; the first constellation point is paired with the second constellation point to generate a constellation combination point;

The receiving module is configured to receive a bit sequence carrying digital information;

The processing module is configured to map the bit sequence to a symbol for transmission by using a mapping table of the constellation combination point, where the mapping table is pre-stored by the encoder;

The sending module is configured to send the symbol to the digital to analog converter.

In another possible implementation, the encoder includes: a transceiver, a processor, and a bus;

The transceiver is coupled to the processor via the bus;

The processor performs the following steps:

Determining a first constellation point from at least two dimensional first constellation diagrams in the multi-dimensional constellation diagram, and determining a second constellation point from the other at least two-dimensional second constellation diagrams in the multi-dimensional constellation diagram, the first constellation point Different from the second constellation point, the constellation point having the largest amplitude in each constellation; pairing the first constellation point with the second constellation point to generate a constellation combination point;

The transceiver performs the following steps:

Receiving a bit sequence carrying digital information;

The processor performs the following steps:

Mapping the bit sequence to a symbol for transmission through a mapping table of the constellation combination point, the mapping table being pre-stored by the encoder;

The transceiver performs the following steps:

The symbol is sent to a digital to analog converter.

In a third aspect, an embodiment of the present application provides a computer storage medium, where the program storage code is stored in the computer storage medium, and the program code is used to indicate that the method of the first aspect or the second aspect is performed.

In the technical solution provided by the embodiment of the present application, in the process of selecting constellation points in other dimensions and pairing to generate constellation combination points, the encoder can discard the constellation combination points generated by the largest constellation points in the constellation diagrams of other dimensions, which can be effective. Reduce the power peak of the constellation combination point, thereby effectively improving the fiber Resistance to nonlinear damage.

DRAWINGS

1 is a schematic diagram of an apparatus of an optical transmission system in an embodiment of the present application;

2 is a schematic diagram of an embodiment of a data modulation method in an embodiment of the present application;

3 is a schematic diagram of a first constellation diagram and a second constellation diagram in the embodiment of the present application;

4 is a schematic diagram of an embodiment of an encoder in an embodiment of the present application;

FIG. 5 is a schematic diagram of another embodiment of an encoder in an embodiment of the present application.

detailed description

The embodiment of the present application provides a data modulation method and an encoder for improving the resistance of an optical fiber to nonlinear damage.

The technical solutions in the embodiments of the present application are clearly and completely described in the following with reference to the drawings in the embodiments of the present application. It is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments obtained by a person skilled in the art based on the embodiments of the present application without creative efforts are within the scope of the present application.

The terms "first", "second", "third", "fourth", etc. (if present) in the specification and claims of the present application and the above figures are used to distinguish similar objects without having to use To describe a specific order or order. It is to be understood that the data so used may be interchanged where appropriate so that the embodiments described herein can be implemented in a sequence other than what is illustrated or described herein. In addition, the terms "comprises" and "comprises" and "the" and "the" are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or device that comprises a series of steps or units is not necessarily limited to Those steps or units may include other steps or units not explicitly listed or inherent to such processes, methods, products or devices.

For a long time, larger transmission capacity, longer transmission distance and better transmission effect are the goals pursued by optical communication systems. In recent years, the rapid increase in transmission distance and capacity brought about by the application of a large number of new technologies has led to the development of optical communication systems exceeding the growth rate defined by Moore's Law. Although the current development of the information industry has slowed down, with the globalization of information and the emergence of new data services, the development of ultra-long-distance, ultra-large-capacity optical communication systems will remain one of the themes of future research. Current optical communication systems are based on high-level mainstream patterns PDM-16QAM, the spectrum efficiency is 8 bits per second per Hz bits / s / Hz 200G solution transmission distance is less than 600 kilometers. If you continue to extend the transmission distance, it will be affected by linear gain (such as OSNR) and fiber nonlinear damage (SPM, XPM, FWM). For the current PDM-16QAM, the joint orthogonal component (English full name: Inphase/Quadrature, referred to as: I/Q) and two polarization states (X, Y) in the four-dimensional vector (Ix, Qx, Iy, Qy) space There is a 16x16=256 combination, referred to as 256 points, and the minimum Euclidean distance is 1.

Referring to the optical transmission system of PDM-16QAM shown in FIG. 1, a transmitter is included in the optical transmission system, and the transmitter includes an encoder for multi-dimensionally encoding binary input data, and a driving signal is generated by a digital-to-analog converter. The drive signal then modulates the various dimensions (amplitude, phase, polarization state, time, etc.) of the optical carrier produced by the laser through a modulator. The modulator consists of a conventional phase/amplitude modulator, phase shifter, Mach-Zehnder interferometer and polarization multiplexer. Then, the optical modulation signal output by the modulator is subjected to a 50% link dispersion precompensation using a dispersion compensation fiber to obtain a symmetric link dispersion distribution, wherein the dispersion precompensation can also be electrically compensated by the transmitter digital signal processing. achieve. The transmission link consists of a single-mode fiber and an optical signal amplifier. The dispersion compensation fiber is used to compensate the residual 50% link dispersion at the end of the link. The residual dispersion compensation can also be realized by the electrical compensation of the receiver digital signal processing. In an end-coherent receiver, an optical mixer mixes the received optical signal with a local oscillator source, and some photodetectors are used to detect the various mixing components produced by the optical mixer. The analog to digital converter samples each of the mixing components, and the digital signal processor recovers information of various dimensions of the optical signal. However, in the PDM-16QAM optical transmission system, there is no compensation design for nonlinear damage, resulting in low resistance of the optical fiber to nonlinear damage.

In order to solve this problem, the embodiment of the present application provides the following technical solution: First, an encoder determines a first constellation point from at least two-dimensional first constellation diagrams in a multi-dimensional constellation, from other at least two dimensions in the multi-dimensional constellation Determining a second constellation point in the second constellation diagram, the first constellation point being different from the second constellation point being the largest constellation point in the respective constellation; then the encoder is to use the first constellation point and the second The constellation points are paired to generate a constellation combination point; the encoder receives a bit sequence carrying digital information; the encoder maps the bit sequence to a symbol for transmission by a mapping table of the constellation combination points prestored by the encoder; the encoding The symbol is sent to the digital to analog converter.

In the embodiment of the present application, the quadrature amplitude modulation is based on including I/Q and other relative to I/Q. The multidimensional constellation of the dimension, and the other dimensions may be at least one of a polarization state, a time, a wavelength, a subcarrier, a mode of a multimode fiber, and a core of the multicore fiber, which is not limited herein.

FIG. 2 is a flowchart of a data modulation method according to an embodiment of the present application. In the data modulation method, the method specifically includes the following steps:

201. The encoder determines a first constellation point from the first constellation diagram of at least two dimensions in the multi-dimensional constellation, and determines a second constellation point from the other at least two-dimensional second constellation diagram in the multi-dimensional constellation, the first When the constellation point is different from the second constellation point, it is the largest constellation point in the respective constellation.

The at least two-dimensional first constellation diagram in the multi-dimensional constellation diagram is a coordinate graph composed of I/Q, the abscissa of the graph is the I, the ordinate of the graph is the Q, and the multi-dimensional constellation is the same. The other at least two-dimensional second constellation diagram in the middle is also a graph composed of I/Q, the abscissa of the graph is the I, and the ordinate of the graph is the Q. The encoder determines the first constellation point from the first constellation map according to the requirement of not selecting the largest constellation point in the constellation diagram, and determines the second constellation point from the second constellation map.

In practical applications, if the multidimensional constellation is PDM-16QAM, at least two dimensions in the multidimensional constellation are the I/Q and the first polarization state, and at least two other dimensions in the multidimensional constellation are the I/Q And the second polarization state, as shown in the multi-dimensional constellation shown in FIG. 3, the multi-dimensional constellation includes a first constellation diagram and a second constellation diagram. The first constellation diagram is the same as the second constellation diagram. It can be understood that the first constellation and the second constellation may have other forms, which are not limited herein. The first constellation diagram includes the I/Q and the first polarization state, and the constellation points in the first constellation diagram are respectively allocated to three circles having a radius of three positive unequal positive numbers with the origin as the center of the circle On the ring, the above three rings are sequentially recorded as ring 1, ring 2 and ring 3 from the inside to the outside, wherein the four constellation points on the ring 1 are respectively (-1+1j), (-1-1j), (1+1j), (1-1j); 8 constellation points assigned to ring 2 are (-1+3j), (-3+1j), (-3-1j), (-1-3j) , (1-3j), (3-1j), (3+1j), (1+3j); the four constellation points assigned to the ring 3 are (-3+3j), (-3-3j), (3-3j), (3+3j); the second constellation diagram includes the I/Q and the second polarization state, and the constellation points in the second constellation diagram are respectively allocated at an origin as a center and three inter-symbols On the three rings whose unequal positive numbers are radii, the above three rings are sequentially recorded as ring 4, ring 5, and ring 6 from the inside to the outside, wherein 4 constellation points are allocated on the ring 4 (-1+1j) ), (-1-1j), (1+1j), (1-1j); 8 constellation points (-1+3j), (-3+1j), (-3-1j) are allocated on the ring 5. , (-1-3j), (1-3j), (3-1j), (3+1j), (1+3j); 4 constellation points (-3+3j) are allocated on the ring 6, (- 3-3j), (3- 3j), (3+3j). The encoder is selecting this The first constellation point and the second constellation point may also be used in the following manners:

In a possible manner, the encoder may select the minimum Euclidean distance between the constellation point with the largest amplitude and the constellation combination point in the constellation diagram at different times as the minimum Euclidean distance between the constellation points of the PDM-16QAM.

The two requirements determine the first constellation point from the first constellation map and the second constellation point from the second constellation map. That is, when the encoder selects any point in the constellation point (-3+3j), (-3-3j), (3-3j), (3+3j) in the first constellation, the encoder cannot be in the second constellation. Select constellation points (-3+3j), (-3-3j), (3-3j), (3+3j). Meanwhile, when the encoder selects (-1+1j) in the first constellation, the encoder can select (-3+1j), (-1+3j), (- in the second constellation diagram. Any point in 3-3j), (-1-1j), (1+1j), (3+3j), (1-3j), (3-1j), when the encoder is in the first constellation diagram When (1+1j) or (-1-1j) is selected, the encoder can select (3+1j), (1+3j), (-3+3j), (-1+) in the second constellation diagram. 1j), any of (1-1j), (3-3j), (-3-1j), (-1-3j); for example, the encoder selects in the first constellation (-3+3j) When the encoder can select (-3+1j), (-1+3j), (-1-1j), (1+1j), (1-3j), (3) in the second constellation diagram Any one of -1j), when the encoder selects (-3+1j) or (-1+3j) in the first constellation, the encoder can select (3+1j) in the second constellation , (1+3j), (-3+3j), (-1+1j), (1-1j), (3-3j), (-3-1j), (-1-3j). Of course, in practical applications, the constellation point selected by the encoder between the first constellation diagram and the second constellation diagram may also be reversed. For example, when the encoder selects (-1+1j) in the first constellation, the encoder can select (3+1j), (1+3j), (-3+3j) in the second constellation. , (-1+1j), (1-1j), (3-3j), (-3-1j), (-1-3j), when the encoder is selected in the first constellation ( When 1+1j) or (-1-1j), the encoder can select (-3+1j), (-1+3j), (-3-3j), (-1-) in the second constellation diagram. 1j), (1+1j), (3+3j), (1-3j), (3-1j). The manner in which the encoder specifically selects the constellation points is not limited herein.

In another possible manner, the encoder may select the minimum Euclidean distance between the constellation point with the largest amplitude and the constellation combination point in the constellation diagram at the same time as the minimum Euclidean distance between the constellation points of the PDM-16QAM.

In addition to these two requirements, any point from the ring 1 is selected as the first constellation point, and a point is selected from the ring 4 or the ring 5 or the ring 6 as the second constellation point. For example, when the encoder selects (-1+1j) in the ring 1 of the first constellation, the encoder can select (-3+1j), (-1+3j) in the second constellation. (-3-3j), (-1-1j), (1+1j), (3+3j), (1-3j), (3-1j) any point when the encoder is in the first constellation When (1+1j) or (-1-1j) is selected in the figure, the encoder can select (3+1j), (1+3j), (-3+3j), (- in the second constellation diagram. 1+1j), (1-1j), (3-3j), (-3-1j), (-1-3j). In practical applications, the constellation point selected by the encoder between the first constellation diagram and the second constellation diagram may also be reversed.

In another possible implementation manner, the encoder may select the minimum Euclidean distance between the constellation point with the largest amplitude and the constellation combination point in the constellation diagram at different times as the minimum Euclidean distance between the constellation points of the PDM-16QAM.

These two requirements are selected from the ring 2 as the first constellation point, and a point is selected from the ring 4 or the ring 5 as the second constellation point. For example, when the encoder selects (-1+3j) from the first constellation diagram, the encoder can select (-3+1j), (-1+3j), (-1-1j) in the second constellation diagram. ), any point in (1+1j), (1-3j), (3-1j), when the encoder selects (1+3j) in the ring 2 of the first constellation, the encoder is In the second constellation diagram, any one of (3+1j), (1+3j), (-1+1j), (1-1j), (-3-1j), (-1-3j) is selected. In practical applications, the constellation point selected by the encoder between the first constellation diagram and the second constellation diagram may also be reversed.

In another possible implementation, when the encoder selects a constellation point (-3+3j) or a constellation point (3-3j) from the ring 3 as the first constellation point, the encoder is from the constellation point (1+ 1j), the constellation point (-1+3j), the constellation point (1-3j) and the constellation point (-1-1j) are arbitrarily selected as the second constellation point;

When the encoder selects a constellation point (-3-3j) or a constellation point (3+3j) from the ring 3 as the first constellation point, the encoder is from the constellation point (3+1j), the constellation point (-1) +1j), the constellation point (-3-1j) and the constellation point (1-1j) are arbitrarily selected as the second constellation point. For example, when the encoder selects (-3+3j) as the first constellation point in the ring 3 of the first constellation, the encoder can select (-1+3j) in the second constellation, ( Any one of 1+1j), (1-3j), (-1-1j), the encoder selects (3+3j) as the first constellation point in the ring 3 of the first constellation diagram, the encoding The device may select (3+1j), (-1+1j), (-3-1j), and (1-1j) any one of the second constellation diagrams as the second constellation point. In practical applications, the constellation point selected by the encoder between the first constellation diagram and the second constellation diagram may also be reversed.

In another possible implementation manner, the encoder selects a constellation point from the ring 3 from the first target constellation point arbitrarily selected in the ring 1, from the arbitrarily selected second target constellation point in the ring 2. +3j) or constellation point (3-3j) as the third target constellation point and select constellation point (-3-3j) or constellation point (3+3j) from the ring 3 as the fourth target constellation point as the first Constellation point; then the encoder selects a fifth target constellation point from the ring 4 or ring 5 or the ring 6, from the ring 4 or the sixth target constellation point selected in the ring 5, from the constellation point (1+ 1j), constellation points (-1+3j), constellation points (1-3j) and constellation points (-1-1j) are randomly selected as the seventh target constellation point and the constellation point (3+1j), constellation point (-1+1j), any point in the constellation point (-3-1j) and the constellation point (1-1j) is selected as the eighth target constellation point as the second constellation point, the first target constellation point and the fifth The minimum Euclidean distance between the constellation combination points generated by the target constellation point pairing is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times, the minimum Euclidean distance between the constellation combination points generated by pairing the second target constellation point and the sixth target constellation point is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times. That is, the encoder can form a 96-point solution.

In another possible implementation manner, the encoder may select the minimum Euclidean distance between the constellation point with the largest amplitude and the constellation combination point in the constellation diagram at different times as the minimum Euclidean distance between the constellation points of the PDM-16QAM.

These two requirements are selected from the ring 1 as the first constellation point, and a point is selected from the ring 5 as the second constellation point. For example, when the encoder selects (-1+1j) in the first constellation, the encoder can select (-1+3j), (-3+1j), (1- in the second constellation diagram. 3j), (3-1j), when the encoder selects (1+1j) or (-1-1j) in the first constellation, the encoder can select in the second constellation ( 1+3j), (3+1j), (-3-1j), (-1-3j). In practical applications, the constellation point selected by the encoder between the first constellation diagram and the second constellation diagram may also be reversed.

In another possible implementation manner, the encoder may select the minimum Euclidean distance between the constellation point with the largest amplitude and the constellation combination point in the constellation diagram at different times as the minimum Euclidean distance between the constellation points of the PDM-16QAM.

These two requirements are selected from the ring 2 as the first constellation point, and a point is selected from the ring 4 as the second constellation point. For example, when the encoder selects (-1+3j) in the first constellation, the encoder can select (-1+1j), (1-1j) any point in the second constellation, the encoding When the device selects (1+3j) in the first constellation, the encoder can select (1+1j), (-1-1j) any point in the second constellation. In practical applications, the constellation point selected by the encoder between the first constellation diagram and the second constellation diagram may also be reversed.

In another possible implementation manner, the encoder may select the minimum Euclidean distance between the constellation point with the largest amplitude and the constellation combination point in the constellation diagram at different times as the minimum Euclidean distance between the constellation points of the PDM-16QAM.

These two requirements are selected from the ring 2 as the first constellation point, and a point is selected from the ring 5 as the second constellation point. For example, when the encoder selects (-1+3j) in the first constellation diagram, the encoder can select (1+3j), (3+1j), (-3-1j) in the second constellation diagram. ), (-1-3j) any point, when the encoder selects (1+3j) in the first constellation, the encoder can select (-1+3j) in the second constellation, (- 3-1j) (3-1j) (1-3j) Any point. In practical applications, the constellation point selected by the encoder between the first constellation diagram and the second constellation diagram may also be reversed.

In another possible implementation manner, the encoder will use an arbitrarily selected seventh target constellation point in the ring 1 and an arbitrarily selected eighth target constellation point in the ring 2 as the first constellation point; the encoder will a ninth target constellation point selected from the ring 4, a tenth target constellation point selected from the ring 5 as the second constellation point, and a constellation combination generated by pairing the seventh target constellation point with the ninth target constellation point The minimum Euclidean distance between points is the minimum Euclidean distance between the constellation points of the PDM-16QAM

The minimum Euclidean distance between the constellation combination points generated by pairing the eighth target constellation point with the tenth target constellation point is the minimum Euclidean distance between the constellation points of the PDM-16QAM

Times. That is, the encoder can form a 64-point solution.

202. The encoder pairs the first constellation point with the second constellation point to generate a constellation combination point.

The encoder pairs the determined first constellation point with the second constellation point to generate a constellation combination point, that is, the encoder determines a bit sequence from the first constellation point and the second constellation point.

203. The encoder determines a mapping table for the constellation combination point and saves the mapping table.

After determining the constellation combination point, the encoder encodes the constellation combination point to determine a mapping table of the constellation combination points.

In practical applications, the encoder can encode the mapping table in different ways for different constellation point combinations. For example, when the 96-point constellation combination point is provided in the embodiment of the present application, the encoder may determine the 96-point constellation combination point by using a combined binary data encoding manner. That is, in a specific encoding process, the encoder combines the adjacent two bit sequences (the first bit sequence and the second bit sequence) by the signal characteristics of the two bit sequences and then encodes them. The signal characteristics here may be any one of a character, a time slot, a wavelength, a subcarrier, a mode of a multimode fiber, and a core of a multi-core fiber. The first bit sequence includes a first sub-packet, a second sub-packet, and a third sub-packet, the second bit sequence includes a fourth sub-packet identical to the first sub-packet, and the same as the second sub-packet a five sub-packet, the same sixth sub-packet as the third sub-packet, the first sub-packet including a constellation combination point of the constellation point in the ring 1 and a constellation point of the ring 5 and a constellation point in the ring 2 With the ring 4 a constellation point composed of constellation points, the second sub-packet comprising a constellation combination point of the constellation point in the ring 2 and a constellation point in the ring 5, the third sub-packet including the constellation point in the ring 1 The constellation point of the ring 4 and the constellation point of the ring 6, the constellation point (-3+3j) or the constellation point (3-3j) in the ring 3 and the constellation point in the ring 4 (1+1j) ), the constellation point (-1+3j) in the ring 5, the constellation point of the constellation point (1-3j) in the ring 5, and any constellation point in the ring 4 (-1-1j) and The constellation point (-3-3j) or constellation point (3+3j) in the ring 3 and the constellation point (3+1j) in the ring 5, the constellation point (-1+1j) in the ring 4, the ring 5 A constellation point consisting of a constellation point (-3-1j) and a constellation point (1-1j) in the ring 4 is arbitrarily selected.

In the 96-point constellation combination point scheme, the encoder is represented by 3 bits according to the constellation points in the first constellation diagram, and the constellation points in the second constellation diagram are represented by 2 bits, the first bit sequence and the The sub-packets in the second bit sequence combine the number of binary coded bits represented by 3 bits, while the sub-packet combination excludes the combination of the third sub-packet and the sixth sub-packet. Then, the encoder has the smallest Euclidean distance according to the adjacent constellation points in the constellation diagram, and the binary bit with the smallest bit gap is encoded, and the same constellation point in the same sub-packet that is not less than the first preset threshold number encodes the same binary. Bits, which require no less than a second predetermined threshold number of different constellation points in the different sub-packets to encode the same binary bit, encode the 96-point constellation combining point. In practical applications, the mapping table obtained by the encoder in the above manner can have various results. The embodiment of the present application is described by way of example only. For example, when the encoder encodes (-1+3j) and (-1+1j) in the first constellation diagram to 000, the encoder can encode the (-1+1j) in the second constellation diagram. 00, encoding (1-1j) in the second constellation diagram as 11, encoding (-3+1j) in the second constellation diagram as 10, (3-1j) in the second constellation diagram Encoding to 01 to obtain the mapping table; or, the encoder encodes (-1+3j) and (-1+1j) in the first constellation into 000, then the encoder in the second constellation (-1+1j) is encoded as 10, (1-1j) in the second constellation diagram is encoded as 11, and (3-1j) in the second constellation diagram is encoded as 00 to obtain the mapping table; or The encoder encodes (-1+3j) and (-1+1j) in the first constellation diagram to 001, and the encoder encodes (-1+1j) in the second constellation diagram to 00, Encoding (1-1j) in the second constellation diagram to 11, encoding (-3+1j) in the second constellation diagram as 10, and encoding (3-1j) in the second constellation diagram as 01 obtains the mapping table; or the encoder encodes (-1+3j) and (-1+1j) in the first constellation diagram to 001, the encoder will (-1 in the second constellation diagram) +1j) coded as 1 0, encoding (1-1j) in the second constellation diagram as 01, The mapping table is obtained by encoding (-3+1j) in the second constellation diagram as 00 and encoding (3-1j) in the second constellation diagram as 11.

The above coding process is only possible to encode a part of the constellation combination point, that is, the encoder can obtain different mapping tables according to different coding methods, and specifically, which mapping table is used by the encoder, and is randomly acquired by the encoder. For example, the encoder can obtain a mapping table as shown in Table 1, Table 2, Table 3, and Table 4, wherein the encoder uses characters as a joint signal feature. Table 1 is a mapping table of sub-packet combinations, Table 2 is a mapping table of a first sub-packet or a fourth sub-packet, Table 3 is a mapping table of a second sub-packet or a fifth sub-packet, and Table 4 is a third sub-table A mapping table for a packet or a sixth sub-packet.

Table 1

Binary value	00000	00001	00010	00011	00100	00101	00110	00111
First constellation	-1+3j	-1+1j	-1+1j	-1+3j	-1+1j	1+3j	1+3j	-1+1j
Second constellation	-1+1j	3-1j	-3+1j	1-1j	-1+3j	1+3j	-1-1j	1-3j
Binary value	10000	10001	10010	10011	10100	10101	10110	10111
First constellation	-3+1j	1-1j	-1-1j	-3+1j	-1-1j	-3-1j	-3-1j	-1-1j
Second constellation	-1+1j	3+1j	-3-1j	1-1j	1+3j	1+1j	-1-1j	-1-3j
Binary value	01000	01001	01010	01011	01100	01101	01110	01111
First constellation	3-1j	1+1j	1+1j	3-1j	1+1j	3+1j	3+1j	1+1j
Second constellation	-1+1j	3+1j	-3-1j	1-1j	1+3j	1+1j	-1-1j	-1-3j
Binary value	11000	11001	11010	11011	11100	11101	11110	11111
First constellation	1-3j	1-1j	1-1j	1-3j	1-1j	-1-3j	-1-3j	1-1j
Second constellation	-1+1j	3-1j	-3+1j	1-1j	-1+3j	1+1j	-1-1j	1-3j

Table 2

Binary value	00000	00001	00010	00011	00100	00101	00110	00111
First constellation	-1+3j	-1+3j	-1+3j	-1+3j	1+3j	1+3j	1+3j	1+3j
Second constellation	1+3j	3+1j	-3-1j	-1-3j	-1+3j	3-1j	-3+1j	1-3j
Binary value	10000	10001	10010	10011	10100	10101	10110	10111
First constellation	-3+1j	-3+1j	-3+1j	-3+1j	-3-1j	-3-1j	-3-1j	-3-1j
Second constellation	3+1j	3+1j	-3-1j	-1-3j	-1+3j	3-1j	-3+1j	1-3j
Binary value	01000	01001	01010	01011	01100	01101	01110	01111
First constellation	3-1j	3-1j	3-1j	3-1j	3+1j	3+1j	3+1j	3+1j
Second constellation	1+3j	3+1j	-3-1j	-1-3j	-1+3j	3-1j	-3+1j	1-3j
Binary value	11000	11001	11010	11011	11100	11101	11110	11111
First constellation	1-3j	1-3j	1-3j	1-3j	-1-3j	-1-3j	-1-3j	-1-3j
Second constellation	1+3j	3+1j	-3-1j	-1-3j	-1+3j	3-1j	-3+1j	1-3j

table 3

Binary value	00000	00001	00010	00011	00100	00101	00110	00111
First constellation	-1+1j	-1+1j	-1+1j	-1+1j	3+3j	3+3j	3+3j	3+3j
Second constellation	3+3j	1+1j	-1-1j	-3-3j	-1+1j	3+1j	-3-1j	1-1j
Binary value	10000	10001	10010	10011	10100	10101	10110	10111
First constellation	-3+3j	-3+3j	-3+3j	-3+3j	-1-1j	-1-1j	-1-1j	-1-1j
Second constellation	-1+3j	1+1j	-1-1j	1-3j	-1+1j	3-3j	-3+3j	1-1j
Binary value	01000	01001	01010	01011	01100	01101	01110	01111
First constellation	3-3j	3-3j	3-3j	3-3j	1+1j	1+1j	1+1j	1+1j
Second constellation	-1+3j	1+1j	-1-1j	1-3j	-1+1j	3-3j	-3+3j	1-1j
Binary value	11000	11001	11010	11011	11100	11101	11110	11111
First constellation	1-1j	1-1j	1-1j	1-1j	-3-3j	-3-3j	-3-3j	-3-3j
Second constellation	3+3j	1+1j	-1-1j	-3-3j	-1+1j	3+1j	-3-1j	1-1j

Table 4

In practical applications, when the receiver side of the optical transmission system performs the decision constellation point, the receiving end can perform calculation in the eight-dimensional space in combination with the two signal features, and the training sequence adopts the formulas MeanA _xr1 , A _xi1 , A _Yr1 , A _yi1 , A _xr2 , A _xi2 , A _yr2 , A _yi2 estimate the respective average values of the 8192 points of the two signal characteristics, and then adopt the following formula:

Mininal(R _xr1 -A _m,xr1 ) ² +(R _xi1 -A _m,xi1 ) ² +(R _yr1 -A _m,yr1 ) ² +(R _yi1 -A _m,yi1 ) ² +(R _xr2 -A _m,xr2 ) ² +(R _xi2 -A _m,xi2 ) ² +(R _yr2 -A _m,yr2 ) ² +(R _yi2 -A _m,yi2 ) ² (m=1,2,...,8192) For the calculation of the Euclidean distance, the point with the smallest distance is selected as the final judgment result. If the encoder adopts the scheme of the 96-point constellation combination point, the receiver end of the optical transmission system can determine the training sequence by using the formulas MeanA _xr , A _xi , A _yr , A _yi when determining the constellation point. The average of 96 points in the signal characteristics, and then use the following formula:

Mininal(R _xr -A _m,xr ) ² +(R _xi -A _m,xi ) ² +(R _yr -A _m,yr ) ² +(R _yi -A _m,yi ) ² (m=1,2 ,...,96) Select the result of the smallest Euclidean distance from the 96 results of each signal feature, and finally make a final decision based on 4*4=16 possibilities of two adjacent characters, which can be extremely Reduce the amount of calculations. Wherein, the receiver end can select a plurality of Euclidean distances among the 96 results of each signal feature, that is, the result of selecting the five Euclidean distances to be the smallest, or the result of selecting the six Euclidean distances, the specific The values are not limited here.

204. The encoder receives a bit sequence carrying digital information.

The encoder receives various bit sequences carrying digital information in an optical transmission system.

205. The encoder maps the bit sequence to the symbol for transmission by using the mapping table.

The encoder maps the bit sequence carrying the digital information through a mapping table pre-stored by the encoder to obtain symbols for transmission.

206. The encoder sends the symbol to the digital to analog converter.

The encoder transmits the obtained symbol for transmission to the data mode converter, so that the digital-to-analog converter transmits the symbol to realize data transmission.

In the embodiment of the present application, the encoder selects constellation points in other dimensions and pairs them to generate constellation combination points, and discards the constellation combination points generated by the largest constellation points in the constellation diagrams of other dimensions, which can effectively reduce the constellation combination. The peak power of the point, which effectively improves the resistance of the fiber to nonlinear damage. At the same time, in the process of encoding the mapping table of the constellation combination points, the encoder can also effectively reduce the power peak of the constellation combination point by discarding the partial constellation combination points, thereby effectively improving the resistance of the optical fiber to nonlinear damage.

The data modulation method in the embodiment of the present application has been described above. The encoder in the embodiment of the present application is described below.

For details, please refer to FIG. 4, an embodiment of an encoder in the embodiment of the present application includes: a processing module 401, a receiving module 402, and a sending module 403.

The processing module 401 is configured to determine a first constellation point from at least two dimensions of the first constellation in the multi-dimensional constellation, and determine a second constellation from the other at least two-dimensional second constellation in the multi-dimensional constellation Point, the first constellation point is different from the second constellation point as a constellation point having the largest amplitude in each constellation; pairing the first constellation point with the second constellation point to generate a constellation combination point;

The receiving module 402 is configured to receive a bit sequence carrying digital information.

The processing module 401 is configured to map the bit sequence to a symbol for transmission by using a mapping table of the constellation combination point, where the mapping table is pre-stored by the encoder;

The sending module 403 is configured to send the symbol to the digital to analog converter.

In combination with the above embodiment, the processing module 401 is configured to perform steps 201 to 203, and step 205;

The receiving module 402 is configured to perform step 204;

The sending module 403 is configured to perform step 206.

Further, the encoder of FIG. 4 can also be used to perform any of the steps performed by the encoder of FIG. 1 or FIG. 2 to implement any of the functions that the encoder of FIG. 1 or FIG. 2 can implement.

In the embodiment of the present application, the processing module 401 selects constellation points in other dimensions and pairs them to generate constellation combination points, and discards the constellation combination points generated by the largest constellation points in the constellation diagrams of other dimensions, which can effectively reduce the constellation. Combine the power peaks of the points to effectively improve the resistance of the fiber to nonlinear damage. At the same time, in the process of encoding the mapping table of the constellation combination points, the processing module 401 can also effectively reduce the power peak of the constellation combination point by discarding the partial constellation combination points, thereby effectively improving the resistance of the optical fiber to nonlinear damage.

Referring to FIG. 5, another embodiment of the encoder in the embodiment of the present application includes: a transceiver 501 and a processor 502. The transceiver 501 and the processor 502 are connected to each other through a bus 503.

The bus 503 may be a peripheral component interconnect (PCI) bus or an extended industry standard architecture (EISA) bus. The bus can be divided into an address bus, a data bus, a control bus, and the like. For the sake of In the representation, only one thick line is shown in FIG. 5, but it does not mean that there is only one bus or one type of bus.

The processor 502 can be a central processing unit (CPU), a network processor (NP) or a combination of a CPU and an NP.

Processor 502 can also further include a hardware chip. The hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The PLD may be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a general array logic (GAL) or any combination.

Referring to FIG. 5, the encoder may further include a memory 504 for storing a mapping table of the constellation combination points.

The memory 504 may include a volatile memory such as a random-access memory (RAM); the memory may also include a non-volatile memory such as a flash memory ( A flash memory, a hard disk drive (HDD) or a solid-state drive (SSD); the memory 504 may also include a combination of the above types of memories.

Alternatively, the memory 504 can also be used to store program instructions, the processor 502 invoking program instructions stored in the memory 504, can perform one or more of the steps of the embodiment shown in FIG. 2, or an alternative embodiment thereof The function that implements the behavior of the encoder in the above method.

The processor 502, using steps 201 to 203 in the above embodiment, and step 205;

The transceiver 501 includes a radio frequency module and an antenna, and the radio frequency module can be connected to the processor 502 through the bus 503. The radio frequency module and the antenna perform step 204 and step 206 in the foregoing embodiment.

In the embodiment of the present application, the processor 502 selects constellation points in other dimensions and pairs them to generate a constellation combination point, and discards the constellation combination points generated by the largest constellation points in the constellation diagrams of other dimensions, which can effectively reduce the constellation. Combine the power peaks of the points to effectively improve the resistance of the fiber to nonlinear damage. At the same time, in the process of encoding the mapping table of the constellation combination points, the processor 502 can also reduce the power peak of the constellation combination point more effectively by discarding the partial constellation combination points, thereby Effectively improve the resistance of the fiber to nonlinear damage.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above integrated unit can be implemented in the form of hardware or in the form of a software functional unit.

The integrated unit, if implemented in the form of a software functional unit and sold or used as a standalone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application, in essence or the contribution to the prior art, or all or part of the technical solution may be embodied in the form of a software product stored in a storage medium. A number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and the like. .

The above embodiments are only used to illustrate the technical solutions of the present application, and are not limited thereto; The present application has been described in detail with reference to the foregoing embodiments, and those skilled in the art should understand that the technical solutions described in the foregoing embodiments may be modified, or some of the technical features may be equivalently replaced. Modifications or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims (19)

1. A data modulation method, the method comprising:

   The encoder determines a first constellation point from at least two dimensional first constellation diagrams in the multi-dimensional constellation diagram, and determines a second constellation point from the other at least two-dimensional second constellation diagrams in the multi-dimensional constellation diagram, the a constellation point is different from the second constellation point as a constellation point having the largest amplitude in the respective constellation diagram, wherein the multidimensional constellation diagram is a constellation diagram including at least 4 dimensions of the joint orthogonal component I/Q;

   The encoder pairs the first constellation point with the second constellation point to generate a constellation combination point;

   The encoder receives a bit sequence carrying digital information;

   The encoder maps the bit sequence through a mapping table of the constellation combination points to symbols for transmission, the mapping table being pre-stored by the encoder;

   The encoder transmits the symbol to a digital to analog converter.
2. The method of claim 1 wherein said multidimensional constellation is polarization multiplexed 16 quadrature amplitude modulated PDM-16QAM, said PDM-16QAM being based on said I/Q, said first polarization state and a four-dimensional space of a second polarization state, the first constellation including the I/Q and the first polarization state, the second constellation including the I/Q and the second polarization state, The first constellation diagram and the second constellation diagram are graphs of 16 constellation points, the abscissa of the graph is the I, and the ordinate of the graph is the Q.
3. The method of claim 2 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

   The encoder arbitrarily selects the first constellation point from the first constellation diagram;

   The encoder selects the second constellation point from the second constellation map, and a minimum Euclidean distance between constellation combination points generated by pairing the first constellation point and the second constellation point is the PDM- Minimum Euclidean distance between constellation points of 16QAM

   

   Times.
4. The method according to claim 2, wherein the first constellation map and the second constellation map are the same as a rectangular constellation;

   The constellation points in the first constellation diagram are respectively allocated on three rings with the origin as the center and three unequal positive numbers as the radius, and the three rings are sequentially recorded as ring 1 from the inside to the outside. , ring 2, ring 3, Wherein the ring 1 is assigned 4 constellation points, the ring 2 is assigned 8 constellation points, and the ring 3 is assigned 4 constellation points;

   The constellation points in the second constellation diagram are respectively allocated on three rings with the origin as the center and three unequal positive numbers as the radius, and the three rings are sequentially recorded as the ring 4 from the inside to the outside. Ring 5, ring 6, wherein the ring 4 is assigned 4 constellation points, the ring 5 is assigned 8 constellation points, and the ring 6 is assigned 4 constellation points.
5. The method of claim 4 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

   The encoder arbitrarily selects the first constellation point from the ring 1;

   The encoder selects the second constellation point from the ring 4 or the ring 5 or the ring 6, between the first constellation point and the constellation combination point generated by pairing the second constellation point The minimum Euclidean distance is the minimum Euclidean distance between the constellation points of the PDM-16QAM

   

   Times.
6. The method of claim 4 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

   The encoder arbitrarily selects the first constellation point from the ring 2;

   The encoder selects the second constellation point from the ring 4 or the ring 5, and the minimum Euclidean distance between the constellation combination points generated by pairing the first constellation point and the second constellation point is The minimum Euclidean distance between the constellation points of PDM-16QAM

   

   Times.
7. The method of claim 4 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

   When the encoder selects a constellation point (-3+3j) or a constellation point (3-3j) from the ring 3 as the first constellation point, the encoder from the constellation point (1+1j), the constellation Point (-1+3j), constellation point (1-3j) and constellation point (-1-1j) are selected as the second constellation point;

   When the encoder selects a constellation point (-3-3j) or a constellation point (3+3j) from the ring 3 as the first constellation point, the encoder is from a constellation point (3+1j), a constellation A point (-1+1j), a constellation point (-3-1j), and a constellation point (1-1j) are arbitrarily selected as the second constellation point.
8. The method of claim 4 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

   The encoder selects a constellation point (-3+3j) from the ring 3 from a first target constellation point arbitrarily selected in the ring 1, from a second target constellation point arbitrarily selected in the ring 2, or a constellation point (3-3j) as a third target constellation point and a constellation point (-3-3j) or a constellation point (3+3j) from the ring 3 as a fourth target constellation point as the first constellation point ;

   a fifth target constellation point selected by the encoder from the ring 4 or the ring 5 or the ring 6, a sixth target constellation point selected from the ring 4 or the ring 5, from a constellation point (1+1j), constellation point (-1+3j), constellation point (1-3j) and constellation point (-1-1j) are randomly selected as the seventh target constellation point and the constellation point (3+1j) , a constellation point (-1+1j), a constellation point (-3-1j), and a constellation point (1-1j) are arbitrarily selected as an eighth target constellation point as the second constellation point, the first target constellation The minimum Euclidean distance between the constellation combination points generated by pairing the points with the fifth target constellation point is the minimum Euclidean distance between the constellation points of the PDM-16QAM

   

   The minimum Euclidean distance between the constellation combination points generated by pairing the second target constellation point with the sixth target constellation point is the minimum Euclidean distance between the constellation points of the PDM-16QAM

   

   Times.
9. The method according to any one of the preceding claims, wherein the encoder further maps the bit sequence to a symbol for transmission by using a mapping table of the constellation combination point, the method further comprising:

   The encoder determines a mapping table of the constellation combination points according to a combined binary data encoding manner.
10. The method according to claim 9, wherein the mapping table of the constellation combination point by the encoder according to the combined binary data encoding manner comprises:

    The encoder determines a number of binary coded bits according to a first preset condition of the first bit sequence and the adjacent second bit sequence joint signal feature, the first bit sequence including a first sub-packet, a second sub-packet, and a a third sub-packet, the second bit sequence including a fourth sub-packet identical to the first sub-packet, a fifth sub-packet identical to the second sub-packet, and a sixth sixth identical to the third sub-packet a sub-packet, the first sub-packet comprising a constellation combination point formed by a constellation point in the ring 1 and a constellation point of the ring 5, and a constellation point in the ring 2 and a constellation point of the ring 4 a constellation combining point, the second sub-packet comprising a constellation group formed by a constellation point in the ring 2 and a constellation point in the ring 5 In conjunction, the third sub-packet includes a constellation point of the constellation point in the ring 1 and a constellation point of the ring 4 and a constellation point of the ring 6, the constellation point in the ring 3 (-3+ 3j) or constellation point (3-3j) and constellation point (1+1j) in said ring 4, constellation point (-1+3j) in said ring 5, constellation point (1-3j) in said ring 5 a constellation combination point formed by any one of the constellation points (-1-1j) in the ring 4 and a constellation point (-3-3j) or a constellation point (3+3j) in the ring 3 and the ring 5 constellation points (3+1j), constellation points (-1+1j) in the ring 4, constellation points (-3-1j) in the ring 5, and constellation points (1-1j) in the ring 4 Any one of the constellation combination points formed by a constellation point;

    The encoder generates the mapping table according to the number of binary coded bits and the second preset condition by the first bit sequence and the second bit sequence.
11. The method according to claim 10, wherein the first preset condition is that the constellation points in the first constellation diagram are represented by 3 bits, and the constellation points in the second constellation diagram are represented by 2 bits. And combining the first bit sequence with the sub-packet in the second bit sequence by 3 bits, wherein the sub-packet combination excludes a combination manner of the third sub-packet and the sixth sub-packet;

    The second preset condition is that the adjacent constellation points in the constellation diagram have the smallest Euclidean distance, and the binary bits of the minimum bit gap are coded, and the same constellation point code of not less than the first preset threshold number in the same sub-packet The same binary bit, the same constellation point of not less than the second predetermined threshold number in different sub-packets encoding the same binary bit;

    The signal is characterized by a character, a time slot, a wavelength, a subcarrier, a mode of a multimode fiber, and a core of a multi-core fiber.
12. The method according to claim 11, wherein the encoder generates the mapping table according to the number of binary coded bits and the second preset condition by the first bit sequence and the second bit sequence. :

    The encoder encodes (-1+3j) and (-1+1j) in the first constellation into 000, then the encoder will (-1+1j) in the second constellation Encoded as 00, encoding (1-1j) in the second constellation diagram as 11, and (-3+1j) in the second constellation diagram as 10, in the second constellation diagram ( 3-1j) encoding 01 to obtain the mapping table;

    or,

    The encoder encodes (-1+3j) and (-1+1j) in the first constellation into 000, then the encoder will (-1+1j) in the second constellation Encoded as 10, in the second constellation diagram (1-1j) coded to 11, encoding (3-1j) in the second constellation diagram to 00 to obtain the mapping table;

    or,

    The encoder encodes (-1+3j) and (-1+1j) in the first constellation diagram to 001, and the encoder will (-1+1j) in the second constellation diagram Encoded as 00, encoding (1-1j) in the second constellation diagram as 11, and (-3+1j) in the second constellation diagram as 10, in the second constellation diagram (3-1j) encoding 01 to obtain the mapping table;

    or,

    The encoder encodes (-1+3j) and (-1+1j) in the first constellation diagram to 001, and the encoder will (-1+1j) in the second constellation diagram Encoded as 10, encoding (1-1j) in the second constellation diagram as 01, and encoding (-3+1j) in the second constellation diagram as 00, in the second constellation diagram (3-1j) Encoded to 11 to obtain the mapping table.
13. The method of claim 4 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

    The encoder arbitrarily selects the first constellation point from the ring 1;

    The encoder arbitrarily selects the second constellation point from the ring 5, and the minimum Euclidean distance between the constellation combination points generated by pairing the second constellation point with the first constellation point is the PDM-16QAM The smallest Euclidean distance between the constellation points

    

    Times.
14. The method of claim 4 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

    The encoder arbitrarily selects the first constellation point from the ring 2;

    The encoder selects the second constellation point from the ring 4, and the minimum Euclidean distance between the constellation combination points generated by the second constellation point and the first constellation point pairing is the PDM-16QAM Minimum Euclidean distance between constellation points

    

    Times.
15. The method of claim 4 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

    The encoder arbitrarily selects the first constellation point from the ring 2;

    The encoder selects the second constellation point from the ring 5, and the minimum Euclidean distance between the constellation combination points generated by the second constellation point and the first constellation point pairing is the PDM-16QAM Minimum Euclidean distance between constellation points

    

    Times.
16. The method of claim 4 wherein the encoder determines a first constellation point from at least two dimensions of the first constellation in the multidimensional constellation, from other at least two dimensions in the multidimensional constellation Determining the second constellation point in the second constellation diagram includes:

    The encoder will use an arbitrarily selected seventh target constellation point from the ring 1 and an arbitrarily selected eighth target constellation point in the ring 2 as the first constellation point;

    The encoder will select a ninth target constellation point from the ring 4, a tenth target constellation point selected from the ring 5 as the second constellation point, the seventh target constellation point and the The minimum Euclidean distance between the constellation combination points generated by the ninth target constellation point pairing is the minimum Euclidean distance between the constellation points of the PDM-16QAM

    

    And a minimum Euclidean distance between the constellation combination points generated by pairing the eighth target constellation point with the tenth target constellation point is a minimum Euclidean distance between constellation points of the PDM-16QAM

    

    Times.
17. The method of claim 1 wherein said other dimensions are at least one of a polarization state, a time, a wavelength, a subcarrier, a mode of a multimode fiber, and a core of a multi-core fiber.
18. An encoder, comprising:

    a processing module, configured to determine a first constellation point from at least two dimensions of the first constellation in the multi-dimensional constellation, and determine a second constellation from another at least two-dimensional second constellation in the multi-dimensional constellation Point, the first constellation point is different from the second constellation point as a constellation point having the largest amplitude in the respective constellation; pairing the first constellation point with the second constellation point to generate a constellation combination point;

    a receiving module, configured to receive a bit sequence carrying digital information;

    The processing module is configured to map the bit sequence through a mapping table of the constellation combination point to a symbol for transmission, where the mapping table is pre-stored by the encoder;

    And a sending module, configured to send the symbol to the digital to analog converter.
19. An encoder, comprising:

    Transceiver, processor, bus;

    The transceiver and the processor are connected by the bus;

    The processor performs the following steps:

    Determining a first constellation point from at least two dimensional first constellation diagrams in the multi-dimensional constellation diagram, and determining a second constellation point from other at least two-dimensional second constellation diagrams in the multi-dimensional constellation diagram, the a constellation point is different from the second constellation point as a constellation point having the largest amplitude in the respective constellation; pairing the first constellation point with the second constellation point to generate a constellation combination point;

    The transceiver performs the following steps:

    Receiving a bit sequence carrying digital information;

    The processor performs the following steps:

    Mapping the bit sequence through a mapping table of the constellation combination points to symbols for transmission, the mapping table being pre-stored by the encoder;

    The transceiver performs the following steps:

    The symbol is sent to a digital to analog converter.

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